It is desirable for people in social groups and business groups to know where other members of the same group are located on a frequent basis. Even if not possible to know the exact location of each group member every minute of the day, it still can be very beneficial to have knowledge of group member location on a less frequent but fairly often basis, e.g., obtaining a location estimation or approximation on an individual to within an hour or to within a couple of hours or at an approximate location (e.g., “at work”). Consider a social group comprising an extended family. For example, parents need to know where their children are after school in order to plan errands, pick them up to transport them home or to various activities, or to know that they are not associating with the wrong types of elements, e.g., hanging out at the pool hall with the motorcycle gang. Similarly, children sometimes need to know where their parents are located. For example, a child may need to know whether each parent is at home, at the office, in transit, at the grocery store purchasing food for dinner, or across town on an errand so that the child can make arrangements to find a parent or another adult for transportation, etc. Further, spouses may want to know when the other spouse is on the golf course, at work, etc. In addition, a family member may want to know when another family member is on an errand, e.g., to the post office, dry cleaners, shopping mall, etc. It is also desirable to be able to keep track of extended family members, such as elderly relatives who may not often leave the home or who may have trouble finding their way around.
However, most people find it burdensome to be continually making telephone calls to let others know where they are. Furthermore, many people with mobile telephones lose them, forget them, or forget to turn them on. This is especially true with children. In addition mobile phone coverage is not seamless, and mobile phones are prohibited or not practical at some locations or during some activities. Some older people do not have, do not know how to use and/or do not desire to use mobile telephones and/or answering machines.
Presently, the Global Positioning System (GPS) can be used to track and locate people and vehicles. However, GPS is expensive, intrusive, and typically requires some effort and cooperation by the person sought to be located. GPS location determination is also dependent upon the GPS receiver's antenna being able to receive signals from a plurality of satellites, e.g., via a line of sight to each satellite, thus making GPS tracking not practical for indoor locating of individuals. For these reasons, GPS generally is not very practical, efficient, or cost-effective for locating individuals, particularly children and the elderly and infirm.
Accordingly, it would be desirable for people in social groups such as families to have an easy, inexpensive, non-intrusive and/or cost-effective way to keep track of each other. People formed into groups for other reasons, e.g., based upon business, civic, volunteer services, clubs, school, or other various associations, could also benefit from such locating methods and apparatus. Methods and apparatus that make use of existing infrastructure and accounting information collected on individuals and/or devices would be beneficial. Methods and apparatus that perform location determinations on members of a group in a passive manner would also be beneficial. It would also be advantageous if such passive capable locating systems also included features allowing members of a group to actively enter location information, e.g., to enhance location determination. It would also be useful if location determinations of one or more members of a group were available for viewing in a user friendly format, e.g., a map format, or some other format, e.g., a format including an audio presentation of the location information.